This invention relates to a vacuum cleaner having a plurality of power modes and more specifically to a power control system for such a cleaner.
Historically, power control systems for vacuum cleaners have been designed to provide a uniform flow of power. In the case of vacuum cleaners with electrical motors, power delivery systems have been designed so as to ensure a continuous flow of electricity to the motor so that the drive shaft driven by the motor runs at a constant rate of revolution.
More recently, developments have been directed towards providing variable speed control for vacuum motors. U.S. Pat. No. 6,008,608, which issued to Holstein et al., discloses a switch and speed control assembly for an electronically controlled vacuum cleaner motor. Holstein et al. ""608 provides a control member coupled to a voltage varying device that regulates the amount of power supplied to the vacuum cleaner motor control circuit. The control member includes a thumb wheel which is operated by the user to manually adjust the voltage varying device to selectively vary the speed of the vacuum cleaner motor. Holstein et al. ""608 teaches that a spring may apply a counterforce to the control member to return the motor speed to a normal operating condition after momentarily engaging a xe2x80x9chigh onxe2x80x9d mode. Thus, in Holstein et al. ""608, the user must manually operate the control member.
In U.S. Pat. No. 4,969,229, which issued to Svanberg et al., a battery operated surface treatment apparatus having a booster function is disclosed in which a separate battery is connected in series with the batteries in the main power supply unit in order to temporarily boost the power. A knob is manually operated to activate the booster function. A timing control is optionally provided to limit the period of operation of the booster function in order to prevent overheating. Svanberg et al. ""229 indicates at column 1, lines 27-31, that the invention is directed to vacuum cleaners not provided with any electronic speed control.
In U.S. Pat. No. 4,811,450, which issued to Steadings, a vacuum cleaner having an auxiliary cleaning means is disclosed. The auxiliary cleaning means of Steadings ""450 includes a flanged portion which is used to divert the suction force in a main suction air channel into an auxiliary cleaning hose. According to Steadings ""450, during auxiliary cleaning, an increased suction force may be created in the auxiliary hose by closing off the air flow in the main suction air channel, thereby relieving part of the load on the common suction motor. Steadings ""450 explains that such relief results in increased rotational speed of the motor, which in turn correspondingly increases the suction air flow in the auxiliary hose. However, Steadings ""450 makes it clear, at column 1, lines 54-60, that in the auxiliary mode, the increase in the operational speed of the suction motor is obtained without requiring any electronic motor control or regulation.
The present invention is directed to a vacuum cleaner having a plurality of power modes, and to a power control system which is capable of maintaining the cleaning performance of the vacuum cleaner in those various power modes and/or of controlling the power output to extend the operational life of a battery operated vacuum cleaner. Briefly, the power control system includes one or more sensors or switches which are used to sense the mode of operation of the vacuum cleaner. Signals from the one or more sensors or switches are then directed to a microprocessor which in turn varies a power supply signal being provided to the vacuum cleaner motor.
In accordance with an aspect of the present invention, there is provided a vacuum cleaner having a plurality of operating modes, comprising:
(i) at least one motor and fan assembly for receiving a power supply signal and producing a suction airflow during use of the vacuum cleaner;
(ii) at least one sensor for automatically sensing a change in the operating mode of said vacuum cleaner and generating a mode signal in response thereto; and
(iii) a microprocessor responsive to said mode signal and adapted to vary said power supply signal.
In a preferred embodiment, the vacuum cleaner has a plurality of distinct operating positions and at least one sensor is adapted to sense a change in the operating mode based on a change in the operating position of said vacuum cleaner.
In another embodiment, the vacuum cleaner comprises a cleaning head and a main casing pivotally connected to said cleaning head, and at least one sensor is adapted to sense when said main casing is positioned generally vertically above said cleaning head to sense that said vacuum cleaner is in standby operating mode.
In yet another embodiment, the vacuum cleaner comprises a cleaning head, a main casing pivotally connected to said cleaning head and an auxiliary hose, and at least one sensor is adapted to sense when said main casing is positioned generally vertically above said cleaning head and said vacuum cleaner is configured such that said auxiliary hose is in airflow communication with said motor and fan assembly and to generate a high flow mode signal in response thereto.
In another embodiment, the vacuum cleaner is an upright vacuum cleaner and further includes an auxiliary hose connectable in airflow communication with said motor and fan member assembly, and a high flow mode sensor for sensing when said auxiliary hose is in use.
More preferably, the vacuum cleaner includes a receptacle for releasably receiving said auxiliary cleaning hose, said high flow mode sensor being provided in said receptacle for sensing when said auxiliary cleaning hose is released from said receptacle.
In an alternative embodiment, the vacuum cleaner further comprises at least one power supply for generating said power supply signal. The power supply may comprise a rechargeable battery.
In an embodiment including a rechargeable battery, the vacuum cleaner preferably includes at least one sensor adapted to sense when said vacuum cleaner is in battery recharge mode and to generate a recharge mode signal in response thereto, said microprocessor being responsive to said recharge mode signal and being adapted to vary said power supply signal to operate said motor in a low flow mode, whereby airflow is produced to cool said battery during recharge.
In another aspect of the present invention, there is provided a vacuum cleaner having a plurality of operating modes, comprising:
(i) suction means for receiving a power supply signal and producing a suction airflow during use of the vacuum cleaner;
(ii) sensor means for sensing a change in the operating mode of said vacuum cleaner and generating a mode signal in response thereto; and
(iii) processor means responsive to said mode signal and adapted to vary said power supply signal.
In a preferred embodiment, the vacuum cleaner has a plurality of distinct operating positions and the sensor means is adapted to sense a change in the operating mode based on a change in the operating position of said vacuum cleaner.
In another embodiment, the sensor means includes a standby mode sensor for sensing a standby mode and generating a standby mode signal in response thereto, said processor means being adapted to vary said power supply signal in response to said standby mode signal so that said suction means is operated at decreased power as compared to normal mode when said vacuum cleaner is used to clean a surface.
In yet another embodiment, the sensor means further includes a high flow mode sensor for sensing a high flow mode and generating a high flow mode signal in response thereto, said processor means being adapted to vary said power supply signal so that said suction means is operated at increased power as compared to the normal mode.
In an embodiment including a rechargeable battery, the vacuum cleaner preferably includes a battery recharge mode sensor for sensing a battery recharge mode and generating a battery recharge mode signal in response thereto, said processor means being adapted to vary said power supply signal to operate said suction means in a low flow mode, so that airflow is produced to cool said battery during recharge.
In yet another aspect of the present invention, there is provided a vacuum cleaner having a plurality of operating modes, comprising:
(i) at least one motor and fan assembly for receiving a power supply signal and producing a suction airflow during use of the vacuum cleaner, said vacuum cleaner having a plurality of distinct operating positions, each of said operating modes corresponding to one of said distinct positions;
(ii) at least one switch for generating a mode signal corresponding to at least one of the operating modes; and
(iii) a microprocessor responsive to said mode signal and adapted to vary said power supply signal.
In one embodiment, the vacuum cleaner includes a standby mode switch for generating a standby mode signal when said vacuum cleaner is in a standby mode position, said processor means being adapted to vary said power supply signal in response to said standby mode signal so that said motor and fan assembly is operated at decreased power as compared to normal mode when said vacuum cleaner is used to clean a surface.
In another embodiment, the vacuum cleaner includes a high flow mode switch for generating a high flow mode signal when said vacuum cleaner is in a high flow mode position, said processor means being adapted to vary said power supply signal in response to said high flow mode signal so that said motor and fan assembly is operated at increased power as compared to normal mode when said vacuum cleaner is used to clean a surface.
In yet another embodiment, the vacuum cleaner includes a battery recharge mode switch for generating a battery recharge mode signal when said vacuum cleaner is in a battery recharge mode position, said processor means being adapted to vary said power supply signal to operate said motor and fan assembly in a low flow mode, so that airflow is produced to cool said battery during recharge.